Is routine post-procedural anticoagulation warranted after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction? Insights from the HORIZONS-AMI trial

Aim: Post-procedural anticoagulation (AC) for routine prophylaxis may be administered after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI), but the risks and benefits of this practice are uncertain. We therefore sought to assess the utility of routine post-procedural AC after primary PCI. Methods and results: Patients undergoing primary PCI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial were grouped according to whether they received post-PCI AC for routine prophylaxis. Outcomes were assessed using propensity-adjusted multivariable analysis. Among 2932 patients in whom primary PCI for STEMI was performed, 869 (29.6%) received post-PCI AC for routine prophylaxis (median duration four days) and 2063 (70.4%) received no post-PCI AC. Time from PCI to ambulation was similar in both groups (median 0.9 vs 1.0 days, p=0.40), although hospitalization was prolonged in patients receiving AC for routine prophylaxis (median 6.0 vs 4.0 days, p<0.0001). After propensity-adjustment, patients who received and did not receive AC for routine prophylaxis after PCI experienced similar rates of 30-day adverse ischemic and major bleeding events. Deep venous thrombosis or pulmonary emboli developed rarely (0.3%) within 30 days, and were not significantly reduced by use of post-PCI AC for routine prophylaxis. Conclusions: In this large-scale prospective study, use of post-procedural AC for routine prophylaxis was relatively common, and was not associated with improved clinical outcomes, although the duration of hospitalization was prolonged. These data suggest that post-PCI AC for routine prophylaxis may not provide benefit after successful primary PCI in patients in whom early ambulation is likely.